Well workover is an important step in oilfield production, and has been a labour intensive industry over the years. At present, traditional equipment, which is used in most oilfields, generally requires at least three workers to operate collaboratively. In operation, at least one worker operates a drifting machine or a workover rig to trip an oil pipe, and at least two other workers lift, and attach or detach an elevator at the wellhead. Especially when conducting a minor workover to the wellhead, the workers suffer from hostile working environment, high labour intensity, as well as potential safety hazard during operation.